THE IRAN AFFAIR: A PRESIDENCY DAMAGED

By R. W. APPLE Jr., Special to the New York Times

Published: November 26, 1986

WASHINGTON, Nov. 25—
After six years of seeming invulnerability, President Reagan has been grievously damaged by the crisis over secret arms shipments to Iran. With a unanimity rare in

Washington, leading Republican and Democratic politicians agreed today that the disclosure of payments to the Nicaraguan rebels and the departure of two White House aides had probably hurt the Administration more than it helped. Some think the damage may be irreparable.

A week of almost unrelieved criticism of Mr. Reagan's secret decision to send arms to Iran, and of startling public bickering among senior Administration officials, has created the image of a President isolated, stuck with an unpopular policy and uncharacteristically defensive. The disclosures today produced a sensation in Washington unmatched, perhaps, since the days of the Watergate crisis.

'Probably No Smoking Gun'

''There is probably no smoking gun here,'' said a man who served in the White House during the Watergate years. ''But there is a new mess in Washington, if not a new Watergate. There will be a whole string of fresh disclosures in the months to come, and that will throw the Administration off stride.

''It will hurt the effort in Nicaragua, it will hurt the campaign against terrorism and it will hurt Reagan - unless, of course, he gets lucky and something happens in Iran that shows he was right after all.''

In the weeks to come, Mr. Reagan seems certain to find his credibility, his competence and his control under stern challenge.

On a personal level, Mr. Reagan remains the most popular President of modern times, and he has shown enormous resilience in the past. But he approaches the last two years of his Administration - a time when the strongest Presidents have seen their power slip slowly away - with the Senate and the House of Representatives under Democratic control, with severe budgetary problems demanding attention and now with months or perhaps even years of investigation and revelation on the horizon.

''We look like liars around the world,'' said an Administration official just below Cabinet level.

A Republican senator said, ''Unless he can regain the confidence of the Washington insiders, the American public and the allies in a hurry, we are going to see a weaker, more troubled Reagan than the one we have known so far.''

A common theme of the President's critics tonight was this: The President decided to run the Iranian operation out of the White House because he did not want the encumbrance of State Department and Congressional involvement; but now he says neither he nor most of his senior associates knew of the payments to the Central American rebels.

At best, politicians said, that demonstrates that Mr. Reagan lacked the capacity or the inclination to manage foreign policy. Senator Sam Nunn, Democrat of Georgia, made a similar point last week, before the latest disclosures, when he said the President's dealings with Iran showed that he was ''not fully aware, or informed, or capable of assimilating all the information that his staff gave him.'' Finding Someone to Blame

The dismissal of Lieut. Col. Oliver L. North from the National Security Council staff, where he was involved both with Iran and the Nicaraguan rebels, or contras, seemed to many an end result of a search for a scapegoat.

Senator Robert C. Byrd of West Virginia, who will be the Democratic majority leader next year, said, ''There is something wrong when the President doesn't know what's going on in the basement of the White House,'' where Colonel North had his office.

A blunter assessment was given by Robert Squier, a leading Democratic electoral strategist, who said: ''It's as if they've rummaged around in the White House archives and found the old Nixon playbook. You throw a couple of lesser people to the wolves, let out a little bit of information and hope that that will work. It won't.''

The danger for Mr. Reagan, of course, is that journalistic and Congressional investigations, which are already well under way, will turn up evidence linking senior officials to the payments to the contras. The inquiries may also develop damaging information about the arms shipments themselves and the negotiations surrounding them, from which the announcements today appeared designed to divert attention. Who's in Charge? A senior European ambassador said he was troubled by what he termed ''the evidence that nobody has really been in charge of foreign policy in this country.''

Until today, he said, he had been telling his government that the Iran controversy would blow over, but now he said he felt everything had changed, ''We now have not just a crisis of judgment, as before,'' he said, ''but a crisis of control and perhaps legality.''

Other envoys said American policy in the Middle East was, as one of them put it, ''in the worst shape it has been in for many years.''

On the domestic scene, the prospects of Vice President Bush, who has so far escaped direct involvement in the Iran affair, seemed to many politicians to have nonetheless suffered considerably. Assessing the effect of recent events on Mr. Bush's undeclared candidacy for the Republican Presidential nomination in 1988, a former Republican Cabinet member said: ''George's problem is that he is a kind of political moon, who generates no light of his own. He has reflected Ronald Reagan's brilliance so far, but now that sun may be setting.'' Shultz Seen as a Winner

Secretary of State George P. Shultz appeared to have emerged as a winner from the chaotic events of recent days, in that one of his nemeses, Vice Adm. John M. Poindexter, will be leaving his post as National Security Adviser, and in that Mr. Reagan has named a commission to study the operational role of the National Security Council, which Mr. Shultz and has aides have been criticizing.

On the other hand, many in the Administration expect Reagan loyalists to try, sooner or later, to punish Mr. Shultz for having tried to distance himself and his department from the Iran policy once it became known.

A major question, in the view of much of political Washington, is the future of Donald T. Regan, the White House chief of staff, part of whose job, presumably, is to keep the President informed of what lesser aides are doing. He is said to have known nothing about the payments to the contras. If that is so, several Republicans said, he must take part of the blame for Mr. Reagan's belated discovery of the possibly illegal diversion of funds.

''I find it inconceivable that they will keep him,'' said a prominent Democrat. ''If I were them, I'd send for Baker in a hurry'' - a reference to Treasury Secretary James A. Baker 3d, Mr. Regan's predecessor at the White House.

HOW ARMS FUNDS WERE DIVERTED: THE MEESE VERSION Account is based on statements by Attorney General Edwin Meese 3d. He placed all transactions between January 1986 and the present. The United States provides approximately $12 million worth of arms to Israel. Israelis sell the arms to ''representatives of Iran.'' The amount of payment, including profits, is negotiated between ''representatives of Israel'' and ''representatives of Iran,'' then transferred to the Israeli representatives. Israeli representatives transfer to the C.I.A. the full amount of money owed to the United States for the arms already supplied plus money for any transportation costs involved. The C.I.A. uses these funds to repay the Department of Defense. Profits - estimated to be between $10 million and $30 million - are then deposited into Swiss bank accounts established by the rebels fighting in Nicaragua. These funds were not touched by any American.